Childhood friends Mark Fritz and Mike Hutchinson had started several businesses by the time they were in college. By the spring of their sophomore year, they really hit on something.

Thirty years later, they’re still doing it.

The founders of Lakeshirts started screen-printing six designs on a plywood printer in Fritz’s Detroit Lakes basement, drying T-shirts on cookie sheets in a couple of secondhand kitchen ovens. They targeted area resorts and colleges and opened a beachfront shop. First-year sales totaled about $13,000.

Fritz and Hutchinson left the basement after the first year, opening a series of manufacturing facilities. They now own a 275,000-square-foot plant, where the atmosphere is so casual that six dogs regularly greet visitors.

Lakeshirts serves resorts, colleges and schools nationwide with 200 styles of apparel in 325 colors. The company can process orders quickly enough to supply fan wear for games in the NCAA Final Four, the college football bowl and College World Series. Last year, sales topped $50 million.

The company used to import 80 percent of its unfinished product and now imports 20 percent. The decision to shift to clothing made in the U.S. (mostly from Los Angeles) has contributed to the quick turnaround time for fan wear.

Fritz is excited about the resurgence of domestic clothing manufacturing.

“Made in the U.S.A. — we’re working hard on that,” he said.

Lakeshirts also works with the Fair Labor Association to ensure its products come from businesses that offer safe working conditions and eschew child labor.

The founders focus on helping their hometown as well, hosting plant tours to encourage young people to consider manufacturing careers. Its artists helped write the design curriculum for Detroit Lakes’ high schools and volunteer weekly to teach elementary school art. The company sponsors the city’s Fourth of July fireworks display, and Fritz leads a local group that is raising $8 million to turn a former ski hill into a year-round public attraction.

“As a company, that’s part of our values — giving back to the community, helping make the community a better place to live, raise our families, work and recreate,” he said.